Preparation to raid in more ways than one...
There's a slight disconnect between the difficulty of the normal version and the heroic version for instances like Stonecore. In the vein of Icecrown Citadel, the heroic fights are ramped up difficulty with extra boss health, more raid and tank damage, and added fight mechanics. The fire on the ground will not be ignored. Neither will those adds, or the spikes. These fights must be executed the way our Blizzard Overlords intended, or there will be no justice points or loot.
And if you haven't gotten the memo, our blue bar is pretty flimsy. We are absolutely unable to heal through stupid; we lack both the brute force and the energy to do so.
It's been near impossible to train myself, but really, those dps do not need to be at full. Everyone just needs to stay alive. With the massive stamina boosts on gear, a 35% full health bar is painful to look at, but enough health for a DPS to survive if someone else is getting hammered or focused. I haven't seen many unavoidable damage types, so these encounters place emphasis on personal survivability and situational awareness.
Situational awareness and You
The less I stare at health bars, the better this whole Cataclysmic healing thing gets. The graphics for what's happening are everywhere, and with two second cast times on my bread-and-butter spells I can start casting and spend almost two full seconds watching the fight. I feel less like I am playing my own mini-game of whack-a-mole while everyone else is playing World of Warcraft than I used to. For now, we're all playing the same game: surviving the encounter.
It's true that the graphics have always been that way, but it has affected my decision-making in new content as though I were raiding. A lot of the attacks that are going to hurt the DPS are visible in the field before they ever tick on the health bars (tank damage, not so much, but properly-geared tanks are lasting so much longer without a heal. It's refreshing).
It's important, at these lower gear levels, to use all the tools available. Cooldowns are godly. I use HoSac quite often now. LoH is amazing if glyphed - 10% mana when the tank needs a huge heal. Divine Favor can potentially burn a lot of mana, but it's great to recover. Freakishly, I've been using it as a mana-saver, when the damage ramps up to still get away with casting Holy Light. Your mileage may vary.
(I'm a bit underwhelmed by our giant glowing angel, but I'm still finding uses for him.)
It's inferior from a time-management standpoint to cast Word of Glory with only one stack of Holy Power, and yet I find myself using it as an emergency on the move so I can use the self-healing of Protector of the Innocent. I haven't decided yet if this is a bad habit or a worthwhile use of time I couldn't be healing otherwise. I know some holy paladin theorycrafters are down on PotI, but I'm finding it well-designed for the encounters and I'm grateful to have it.
(I originally said it was mathematically inferior to cast a 1 HP WoG, but ithilyn corrected me. See comments below for some clarification.)
What are you experiences in the new heroics?